Troubleshooting Intermittent Call Disconnects

mumbles202 · ‎08-02-2017

I'm working on a CUCM 7.1 that was deployed years ago w/ 2 sites. It is a single server setup w/ a VG at both offices. outbound calls route out through the main office and inbound calls for the remote office come in over POTS on a 2901, w/ a connection plar to the extension defined in CUCM. Each user in the remote office has a DID on one of the inbound POTS lines lines, but one of the users is intermittently getting either voice quality issues or disconnects. The local Telco has been out numerous times and verified there are no issues on the line. And since it's happening on both inbound and outbound calls I suspect it has more to do w/ the connection, but I'm not sure the best way to determine the cause of the random disconnects. The last reported issue was after 20 minutes. The 2 offices are connected via a vpn, but as this is the only user having an issue it's hard to point to the ISP for this. The remote office is a small 4 user location w/ all users connecting to the same PoE switch for their phones as well. Anything I can look at in particular to find out why?

Gregory Brunn · ‎08-02-2017

One user reporting the problem on one phone. Have you changed the phone or checked out if the switch port is having CRC issues indicating a problem with cabling to that phone?

Change out that one port, see if it makes a difference.

Also probably time to get that 7.1 upgraded long past end of support.

mumbles202 · ‎08-03-2017

Thanks for responding. I haven't changed the phone but have changed the handset and the cord to rule that out. A second user who has the same dn on a sidecar did mention the static on one inbound call a few weeks ago which led me to believe it was the line from the Telco. The switch port itself doesn't have any errors, but I can certainly try another port.

I noticed in the debugs on the gateway for one of the disconnected calls that I have this right at the time of the disconnect:

cch323_gw_process_read_socket: H.245 socket error

Yes, agreed about the upgrade.

mumbles202 · ‎08-09-2017

I spoke to the users at the remote site and over the last 2 days the issue has re-occurred. The DID in question has a PLAR to a DN that is defined on 2 phones at the remote location. At least twice in the last few days the other user who has the DN has answered an inbound call and advised they heard static as well. I'm considering swapping the ports on the FXO card to see if the issue continues.

Since all outbound calls go out over a PRI from the main office and only 1 user has advised of any issue with outbound I'm suspecting that is a line cord or phone issue.